This invention relates to evaporative devices, and more particularly to a device in which a vaporizable liquid is vaporized and mixed with air and then introduced into the desired environment.
The use of vaporizable substances to freshen the air in a room or other enclosed space is well known. A number of devices attempt to accomplish that end, some of which use vaporizable solid materials positioned within a free-standing container that includes apertures to permit the vapor to escape therethrough. The normal convective air currents are utilized to distribute the vapor through the room as the material sublimes and passes through the apertures provided in the container. Although such products are effective to a certain degree, greater effectiveness is obtained when the desired vapors are introduced into the air and distributed in a more forceful fashion than normal convective currents provide. For example, in U.S. Pat. No. 3,990,848, issued Nov. 9, 1976, there is disclosed the use of a battery powered fan which causes the flow of the air through a container within which is positioned a gel-type product which it is desired to introduce into the air. The gel-type product is contained within a porous container which is positioned within the outer container and which also carries a battery. When the material to be vaporized is exhausted the porous container and its associated battery are discarded and a new unit is installed. However, the battery life may exceed the life of the material to be evaporated, or the material may not have been consumed at the time the battery has failed, and in those cases discarding the battery-porous container combination is wasteful and uneconomical.
Another arrangement whereby a vaporizable material may be introduced into the air is disclosed in U.S. Pat. No. 4,035,451, issued July 12, 1977, which discloses a further variation in the concept and involves impregnating an accordian pleated absorptive material with the product to be evaporated and positioning it in a cartridge around a centrally positioned battery, which powers the driving fan. Again, however, failure or exhaustion of one of the two elements of the cartridge requires disposal of the complete cartridge and substitution with a fresh cartridge even though one of the two elements might still be usable.
Additionally, in each of the patented devices described above, there is no direct indication given the user that one of the elements of the cartridge requires replacement. The only way a user can determine if the battery has failed is to attempt to determine whether flow is taking place through the device, which would involve opening the device to ascertain whether the fan was operating. Likewise, the only way a user could determine if the vaporizable material had been exhausted is to somehow determine by odor or otherwise that replacement of the vaporizable material is required.
It is an object of this invention to overcome the deficiencies in the above-described devices and to provide an improved, forced-flow, fan-type evaporative device to introduce a vaporizable material into the air within a predetermined environment, and to facilitate the determination of when either the battery providing the power to drive the fan must be replaced or when the source of the vaporizable material must be replaced in order to continue to obtain the benefits of the device.